Objective: The aim of this study was to evaluate cell proliferation rate of cells exfoliated from clinically healthy mucosa of crack cocaine users. Material and Methods: Oral smears were collected from tongue and floor of the mouth mucosa of 87 individuals divided into three groups: crack cocaine users (CrCo), n=26; smokers/alcohol drinkers (SA), n=26 and controls (C), n=35. Histological slides were silver-stained using AgNOR technique to evaluate cell proliferation rate. Images were obtained by an image capturing system adapted to a light microscope at x1000 magnification. Quantification considered 50 cells by smear in which the number of AgNOR dots was visually counted. Mean AgNOR numbers per nucleus (mAgNOR) and the percentage of cells with more than 1,2,3 and 4 AgNORs per nucleus (pAgNOR>1,>2>3 an>4) were calculated. Results: Cells exfoliated from tongue mucosa of SA (3.34±0.51 AgNOR/nucleus) exhibit higher cell proliferation rate (p<0.05) when compared to C (2.81±0.773 AgNORs/nucleus) and to CrCo (2.87±0.51 AgNORs/nucleus). An increase (p<0.05) in mAgNOR was also observed in floor of the mouth cells (3.55±0.57) in SA when compared to C (3.18±0.53) and CrCo (3.28±0.39). Similar findings were found using pAgNOR>1,>2,>3 e >4. Conclusion: Crack cocaine users did not present changes in cell proliferation rate of oral mucosa. Between the expositions studied here, cigarette smoking in combination with alcohol consumption remain as the most harmful factors to oral mucosa.